| abstract |
The present invention provides tooth whitening compositions in the form of a liquid crystal or a microemulsion that includes a tooth whitening agent in an amount effective to whiten teeth, a hydrophilic phase including water, a hydrophobic phase including at least one oil, at least one anionic, nonionic, amphoteric or zwitterionic surfactant, and a water soluble co-solvent having a Hildebrand solubility parameter above 12 (cal/cm 3 ) ½ , as well as methods for whitening teeth including applying the liquid crystal or microemulsion composition to the teeth for a period of time and under conditions effective to whiten the teeth. |